Updated Wed 9 Oct 2013In a four-year study, weekly records of prices of nearly 100 different frozen fillets of cod, haddock and Alaska pollock were collated for seven UK supermarkets. The most striking result from the analysis is that line-caught fish achieved a price premium of some twenty-two percent.

“The fact that the chains choose to label products with ‘line-caught’ is probably related to the fact that the capture method is perceived to be more gentle on the seabed and thus fits well into chain's endeavours by acting responsibly”, says Geir Sogn-Grundvåg, senior scientist at Nofima, who carried out the study.

However, the label 'line-caught' can be deceptive. Fish caught on handlines by artisanal fishermen is relatively environmentally friendly, whereas industrial longline fishing is hugely destructive with regular bycatch of cetaceans, seabirds, turtles, sharks and other vulnerable marine life.

If the fish buying public are prepared to pay nearly a quarter more for fish harvested by less destructive methods, then there is almost certainly a lucrative market for fish labelled '100% bycatch-free', and caught without harming non-target marine wildlife at all.